The influence of plasma spraying parameters on the microstructure and properties of ZRO2-8Y2O3 coatings

Abstract

The microstructure and mechanical properties of yttria stabilized zirconia (YSZ) coatings deposited by atmospheric plasma spray deposition technique have been investigated. The 8YSZ coatings (8 mol % yttria) were deposited onto stainless steel substrates by varying the feedstock powder characteristics. The failure occurring during scratch testing was examined with an optical microscope and scanning electron microscope (SEM) and microstructure was investigated using X-ray diffraction (XRD) as well. The feedstock powder characteristics, crystal structure were examined and correlated to the mechanical behavior and the failure mechanism of the coatings. Different types of failure were observed after scratch testing YSZ coatings of different spraying characteristics. Cracking occurs inside of the scratch track without extensive chipping. The micromechanical mechanism was studied on the basis of shear, fracture and elasticity effects